Semiconductor lasers stabilized to spectral holes in rare earth crystals to a part in 1013 and their application to devices and spectroscopy

Single-frequency diode lasers have been stabilized to 200 Hz at 1.5 μm and independently to 20 Hz at 793 nm over 10-ms integration times using narrow spectral holes in the absorption lines of Er3+- and Tm3+-doped cryogenic crystals as frequency references. Kilohertz stability over 100-s integration times is provided by these techniques, and that performance should be extendable to long integration times with further development. The achieved frequency stabilization provides ideal lasers for high-resolution spectroscopy in the time and frequency domains, real time analog optical signal processing based on spatial-spectral holography, interferometry, and other applications requiring ultra-narrow-band light sources or coherent detection. The stabilized lasers have enabled demonstrations of analog optical signal processing in Er3+ materials at 0.5 GHz bandwidths at temperatures of 4.2 K, and they will be important for electromagnetically induced transparency and quantum information demonstrations.